Implement skeleton of search bar

[wlach]

The search bar is going to be a complicated beast to get right, but we have to get started somewhere. GLAM's search bar looks pretty nice and seems like a reasonable starting point for our own implementation:

It is defined here:

https://github.com/mozilla/glam/tree/main/src/components/search

For populating the actual content based on user input, I have started a skeleton prototype of a metadata-extraction script using lunr.js here -- it's very incomplete and probably slightly broken, but it illustrates how one would extract search metadata from ping files.

On the client side, we would automatically load the lunr data on any page load (hopefully we can keep the size reasonable) which would include the search data + just enough metadata to populate the search bar. Typing stuff into the search bar would then activate lunr. You can see some very rough client side code which I prototyped for the schema dictionary here: wlach/schema-dictionary@97b71d1

I suspect it might be on me to produce at least the first draft on this, but putting this up here in the interests of working in the open.

[wlach]

Going to work on this in the new year -- assigning to myself to make this more clear.

[wlach]

I worked a little bit on this, and it's becoming clear that this is going to be kinda confusing given the number of applications that most of our metrics are currently duplicated across. It's also not 100% clear to me that this (rather complex) feature is actually required at this juncture. I'm going to put this in the backlog, we can always return to it later.

[wlach]

Now that we've consolidated metrics for application variants together, this feature is a bit more tractable.

Note to self: we could also consider using something like Algolia here: https://www.algolia.com/ -- I think rolling our own is probably the right call, but we should see how it goes.